This invention relates to the field of formed openings in poured concrete walls.
Numerous window and door forms have been developed over the years for use in poured concrete walls, such as building foundations and the like. Such forms have been constructed of wood, pressed paper pulp, and metal to provide both repeated use and disposability. To provide adjustment to accommodate varying thicknesses of concrete walls, the forms have been made with contiguous sliding members as in the Roedig U.S. Pat. No. 1,881,971. Forms having multiple sets of various sizes to mix and match are taught in the Shields U.S. Pat. No. 2,787,820. Forms with hollowed dowels of various lengths are provided in a French Pat. No. 911,523. Prior art forms have been constructed of separate supported vertical side members, as well as full rectangular frames. Such prior art forms have been beveled on as many as three sides, so as to facilitate extraction without damage to the concrete. Despite these improvements and many others, no previous form has provided the features of the present invention.
It is an objective of the present invention to eliminate the inherent adjustment problems in prior forms by providing nonsliding self-contained adjustment while utilizing one set of forms.
Another objective is to provide a reusable and easily maneuverable form that is relatively inexpensive to construct and which allows the builder a style option.
A further objective of the present invention is to maximize light inflow through a window installed in an opening formed by the invention.